A Study on Barc Endpoint Profile Transformation Caused by Different Metal/Via Reticle Transmission Ratio in Oxide trench Etch Processes : APC: Advanced Process Control

This paper presents a novel approach of using the Reticle Transmission (RT) ratio of Via and metal to understand the endpoint profile of a BARC/Silicon Nitride (Nitride) etch. This study was conducted on Via first dual damascene process which uses an endpoint method to control the BARC/Nitride etch step. The aim of this study is to use the RT ratio to make predictions on endpoint profile for new products and allow system to select the best recipe. With this new method, it will reduce machine endpoint faults which may arise from products with a wide range of metal and via RT values.